net/rxrpc/call_object.c

   1 /* RxRPC individual remote procedure call handling
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16 #include <linux/circ_buf.h>
  17 #include <linux/spinlock_types.h>
  18 #include <net/sock.h>
  19 #include <net/af_rxrpc.h>
  20 #include "ar-internal.h"
  21
  22 /*
  23  * Maximum lifetime of a call (in jiffies).
  24  */
  25 unsigned int rxrpc_max_call_lifetime = 60 * HZ;
  26
  27 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
  28         [RXRPC_CALL_UNINITIALISED]              = "Uninit  ",
  29         [RXRPC_CALL_CLIENT_AWAIT_CONN]          = "ClWtConn",
  30         [RXRPC_CALL_CLIENT_SEND_REQUEST]        = "ClSndReq",
  31         [RXRPC_CALL_CLIENT_AWAIT_REPLY]         = "ClAwtRpl",
  32         [RXRPC_CALL_CLIENT_RECV_REPLY]          = "ClRcvRpl",
  33         [RXRPC_CALL_SERVER_PREALLOC]            = "SvPrealc",
  34         [RXRPC_CALL_SERVER_SECURING]            = "SvSecure",
  35         [RXRPC_CALL_SERVER_ACCEPTING]           = "SvAccept",
  36         [RXRPC_CALL_SERVER_RECV_REQUEST]        = "SvRcvReq",
  37         [RXRPC_CALL_SERVER_ACK_REQUEST]         = "SvAckReq",
  38         [RXRPC_CALL_SERVER_SEND_REPLY]          = "SvSndRpl",
  39         [RXRPC_CALL_SERVER_AWAIT_ACK]           = "SvAwtACK",
  40         [RXRPC_CALL_COMPLETE]                   = "Complete",
  41 };
  42
  43 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
  44         [RXRPC_CALL_SUCCEEDED]                  = "Complete",
  45         [RXRPC_CALL_REMOTELY_ABORTED]           = "RmtAbort",
  46         [RXRPC_CALL_LOCALLY_ABORTED]            = "LocAbort",
  47         [RXRPC_CALL_LOCAL_ERROR]                = "LocError",
  48         [RXRPC_CALL_NETWORK_ERROR]              = "NetError",
  49 };
  50
  51 const char rxrpc_call_traces[rxrpc_call__nr_trace][4] = {
  52         [rxrpc_call_new_client]         = "NWc",
  53         [rxrpc_call_new_service]        = "NWs",
  54         [rxrpc_call_queued]             = "QUE",
  55         [rxrpc_call_queued_ref]         = "QUR",
  56         [rxrpc_call_connected]          = "CON",
  57         [rxrpc_call_release]            = "RLS",
  58         [rxrpc_call_seen]               = "SEE",
  59         [rxrpc_call_got]                = "GOT",
  60         [rxrpc_call_got_userid]         = "Gus",
  61         [rxrpc_call_got_kernel]         = "Gke",
  62         [rxrpc_call_put]                = "PUT",
  63         [rxrpc_call_put_userid]         = "Pus",
  64         [rxrpc_call_put_kernel]         = "Pke",
  65         [rxrpc_call_put_noqueue]        = "PNQ",
  66         [rxrpc_call_error]              = "*E*",
  67 };
  68
  69 struct kmem_cache *rxrpc_call_jar;
  70 LIST_HEAD(rxrpc_calls);
  71 DEFINE_RWLOCK(rxrpc_call_lock);
  72
  73 static void rxrpc_call_timer_expired(unsigned long _call)
  74 {
  75         struct rxrpc_call *call = (struct rxrpc_call *)_call;
  76
  77         _enter("%d", call->debug_id);
  78
  79         if (call->state < RXRPC_CALL_COMPLETE)
  80                 rxrpc_queue_call(call);
  81 }
  82
  83 /*
  84  * find an extant server call
  85  * - called in process context with IRQs enabled
  86  */
  87 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
  88                                               unsigned long user_call_ID)
  89 {
  90         struct rxrpc_call *call;
  91         struct rb_node *p;
  92
  93         _enter("%p,%lx", rx, user_call_ID);
  94
  95         read_lock(&rx->call_lock);
  96
  97         p = rx->calls.rb_node;
  98         while (p) {
  99                 call = rb_entry(p, struct rxrpc_call, sock_node);
 100
 101                 if (user_call_ID < call->user_call_ID)
 102                         p = p->rb_left;
 103                 else if (user_call_ID > call->user_call_ID)
 104                         p = p->rb_right;
 105                 else
 106                         goto found_extant_call;
 107         }
 108
 109         read_unlock(&rx->call_lock);
 110         _leave(" = NULL");
 111         return NULL;
 112
 113 found_extant_call:
 114         rxrpc_get_call(call, rxrpc_call_got);
 115         read_unlock(&rx->call_lock);
 116         _leave(" = %p [%d]", call, atomic_read(&call->usage));
 117         return call;
 118 }
 119
 120 /*
 121  * allocate a new call
 122  */
 123 struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
 124 {
 125         struct rxrpc_call *call;
 126
 127         call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
 128         if (!call)
 129                 return NULL;
 130
 131         call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
 132                                     sizeof(struct sk_buff *),
 133                                     gfp);
 134         if (!call->rxtx_buffer)
 135                 goto nomem;
 136
 137         call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
 138         if (!call->rxtx_annotations)
 139                 goto nomem_2;
 140
 141         setup_timer(&call->timer, rxrpc_call_timer_expired,
 142                     (unsigned long)call);
 143         INIT_WORK(&call->processor, &rxrpc_process_call);
 144         INIT_LIST_HEAD(&call->link);
 145         INIT_LIST_HEAD(&call->chan_wait_link);
 146         INIT_LIST_HEAD(&call->accept_link);
 147         INIT_LIST_HEAD(&call->recvmsg_link);
 148         INIT_LIST_HEAD(&call->sock_link);
 149         init_waitqueue_head(&call->waitq);
 150         spin_lock_init(&call->lock);
 151         rwlock_init(&call->state_lock);
 152         atomic_set(&call->usage, 1);
 153         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
 154
 155         memset(&call->sock_node, 0xed, sizeof(call->sock_node));
 156
 157         /* Leave space in the ring to handle a maxed-out jumbo packet */
 158         call->rx_winsize = rxrpc_rx_window_size;
 159         call->tx_winsize = 16;
 160         call->rx_expect_next = 1;
 161         return call;
 162
 163 nomem_2:
 164         kfree(call->rxtx_buffer);
 165 nomem:
 166         kmem_cache_free(rxrpc_call_jar, call);
 167         return NULL;
 168 }
 169
 170 /*
 171  * Allocate a new client call.
 172  */
 173 static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx,
 174                                                   gfp_t gfp)
 175 {
 176         struct rxrpc_call *call;
 177
 178         _enter("");
 179
 180         call = rxrpc_alloc_call(gfp);
 181         if (!call)
 182                 return ERR_PTR(-ENOMEM);
 183         call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
 184         call->service_id = srx->srx_service;
 185         call->tx_phase = true;
 186
 187         _leave(" = %p", call);
 188         return call;
 189 }
 190
 191 /*
 192  * Initiate the call ack/resend/expiry timer.
 193  */
 194 static void rxrpc_start_call_timer(struct rxrpc_call *call)
 195 {
 196         unsigned long expire_at;
 197
 198         expire_at = jiffies + rxrpc_max_call_lifetime;
 199         call->expire_at = expire_at;
 200         call->ack_at = expire_at;
 201         call->resend_at = expire_at;
 202         call->timer.expires = expire_at;
 203         add_timer(&call->timer);
 204 }
 205
 206 /*
 207  * set up a call for the given data
 208  * - called in process context with IRQs enabled
 209  */
 210 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 211                                          struct rxrpc_conn_parameters *cp,
 212                                          struct sockaddr_rxrpc *srx,
 213                                          unsigned long user_call_ID,
 214                                          gfp_t gfp)
 215 {
 216         struct rxrpc_call *call, *xcall;
 217         struct rb_node *parent, **pp;
 218         const void *here = __builtin_return_address(0);
 219         int ret;
 220
 221         _enter("%p,%lx", rx, user_call_ID);
 222
 223         call = rxrpc_alloc_client_call(srx, gfp);
 224         if (IS_ERR(call)) {
 225                 _leave(" = %ld", PTR_ERR(call));
 226                 return call;
 227         }
 228
 229         trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage),
 230                          here, (const void *)user_call_ID);
 231
 232         /* Publish the call, even though it is incompletely set up as yet */
 233         write_lock(&rx->call_lock);
 234
 235         pp = &rx->calls.rb_node;
 236         parent = NULL;
 237         while (*pp) {
 238                 parent = *pp;
 239                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 240
 241                 if (user_call_ID < xcall->user_call_ID)
 242                         pp = &(*pp)->rb_left;
 243                 else if (user_call_ID > xcall->user_call_ID)
 244                         pp = &(*pp)->rb_right;
 245                 else
 246                         goto error_dup_user_ID;
 247         }
 248
 249         rcu_assign_pointer(call->socket, rx);
 250         call->user_call_ID = user_call_ID;
 251         __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 252         rxrpc_get_call(call, rxrpc_call_got_userid);
 253         rb_link_node(&call->sock_node, parent, pp);
 254         rb_insert_color(&call->sock_node, &rx->calls);
 255         list_add(&call->sock_link, &rx->sock_calls);
 256
 257         write_unlock(&rx->call_lock);
 258
 259         write_lock(&rxrpc_call_lock);
 260         list_add_tail(&call->link, &rxrpc_calls);
 261         write_unlock(&rxrpc_call_lock);
 262
 263         /* Set up or get a connection record and set the protocol parameters,
 264          * including channel number and call ID.
 265          */
 266         ret = rxrpc_connect_call(call, cp, srx, gfp);
 267         if (ret < 0)
 268                 goto error;
 269
 270         trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage),
 271                          here, ERR_PTR(ret));
 272
 273         spin_lock_bh(&call->conn->params.peer->lock);
 274         hlist_add_head(&call->error_link,
 275                        &call->conn->params.peer->error_targets);
 276         spin_unlock_bh(&call->conn->params.peer->lock);
 277
 278         rxrpc_start_call_timer(call);
 279
 280         _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
 281
 282         _leave(" = %p [new]", call);
 283         return call;
 284
 285         /* We unexpectedly found the user ID in the list after taking
 286          * the call_lock.  This shouldn't happen unless the user races
 287          * with itself and tries to add the same user ID twice at the
 288          * same time in different threads.
 289          */
 290 error_dup_user_ID:
 291         write_unlock(&rx->call_lock);
 292         ret = -EEXIST;
 293
 294 error:
 295         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 296                                     RX_CALL_DEAD, ret);
 297         trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
 298                          here, ERR_PTR(ret));
 299         rxrpc_release_call(rx, call);
 300         rxrpc_put_call(call, rxrpc_call_put);
 301         _leave(" = %d", ret);
 302         return ERR_PTR(ret);
 303 }
 304
 305 /*
 306  * Set up an incoming call.  call->conn points to the connection.
 307  * This is called in BH context and isn't allowed to fail.
 308  */
 309 void rxrpc_incoming_call(struct rxrpc_sock *rx,
 310                          struct rxrpc_call *call,
 311                          struct sk_buff *skb)
 312 {
 313         struct rxrpc_connection *conn = call->conn;
 314         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 315         u32 chan;
 316
 317         _enter(",%d", call->conn->debug_id);
 318
 319         rcu_assign_pointer(call->socket, rx);
 320         call->call_id           = sp->hdr.callNumber;
 321         call->service_id        = sp->hdr.serviceId;
 322         call->cid               = sp->hdr.cid;
 323         call->state             = RXRPC_CALL_SERVER_ACCEPTING;
 324         if (sp->hdr.securityIndex > 0)
 325                 call->state     = RXRPC_CALL_SERVER_SECURING;
 326
 327         /* Set the channel for this call.  We don't get channel_lock as we're
 328          * only defending against the data_ready handler (which we're called
 329          * from) and the RESPONSE packet parser (which is only really
 330          * interested in call_counter and can cope with a disagreement with the
 331          * call pointer).
 332          */
 333         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
 334         conn->channels[chan].call_counter = call->call_id;
 335         conn->channels[chan].call_id = call->call_id;
 336         rcu_assign_pointer(conn->channels[chan].call, call);
 337
 338         spin_lock(&conn->params.peer->lock);
 339         hlist_add_head(&call->error_link, &conn->params.peer->error_targets);
 340         spin_unlock(&conn->params.peer->lock);
 341
 342         _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
 343
 344         rxrpc_start_call_timer(call);
 345         _leave("");
 346 }
 347
 348 /*
 349  * Queue a call's work processor, getting a ref to pass to the work queue.
 350  */
 351 bool rxrpc_queue_call(struct rxrpc_call *call)
 352 {
 353         const void *here = __builtin_return_address(0);
 354         int n = __atomic_add_unless(&call->usage, 1, 0);
 355         if (n == 0)
 356                 return false;
 357         if (rxrpc_queue_work(&call->processor))
 358                 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
 359         else
 360                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 361         return true;
 362 }
 363
 364 /*
 365  * Queue a call's work processor, passing the callers ref to the work queue.
 366  */
 367 bool __rxrpc_queue_call(struct rxrpc_call *call)
 368 {
 369         const void *here = __builtin_return_address(0);
 370         int n = atomic_read(&call->usage);
 371         ASSERTCMP(n, >=, 1);
 372         if (rxrpc_queue_work(&call->processor))
 373                 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
 374         else
 375                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 376         return true;
 377 }
 378
 379 /*
 380  * Note the re-emergence of a call.
 381  */
 382 void rxrpc_see_call(struct rxrpc_call *call)
 383 {
 384         const void *here = __builtin_return_address(0);
 385         if (call) {
 386                 int n = atomic_read(&call->usage);
 387
 388                 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
 389         }
 390 }
 391
 392 /*
 393  * Note the addition of a ref on a call.
 394  */
 395 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 396 {
 397         const void *here = __builtin_return_address(0);
 398         int n = atomic_inc_return(&call->usage);
 399
 400         trace_rxrpc_call(call, op, n, here, NULL);
 401 }
 402
 403 /*
 404  * Detach a call from its owning socket.
 405  */
 406 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 407 {
 408         const void *here = __builtin_return_address(0);
 409         struct rxrpc_connection *conn = call->conn;
 410         bool put = false;
 411         int i;
 412
 413         _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
 414
 415         trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage),
 416                          here, (const void *)call->flags);
 417
 418         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 419
 420         spin_lock_bh(&call->lock);
 421         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
 422                 BUG();
 423         spin_unlock_bh(&call->lock);
 424
 425         del_timer_sync(&call->timer);
 426
 427         /* Make sure we don't get any more notifications */
 428         write_lock_bh(&rx->recvmsg_lock);
 429
 430         if (!list_empty(&call->recvmsg_link)) {
 431                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
 432                        call, call->events, call->flags);
 433                 list_del(&call->recvmsg_link);
 434                 put = true;
 435         }
 436
 437         /* list_empty() must return false in rxrpc_notify_socket() */
 438         call->recvmsg_link.next = NULL;
 439         call->recvmsg_link.prev = NULL;
 440
 441         write_unlock_bh(&rx->recvmsg_lock);
 442         if (put)
 443                 rxrpc_put_call(call, rxrpc_call_put);
 444
 445         write_lock(&rx->call_lock);
 446
 447         if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 448                 rb_erase(&call->sock_node, &rx->calls);
 449                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
 450                 rxrpc_put_call(call, rxrpc_call_put_userid);
 451         }
 452
 453         list_del(&call->sock_link);
 454         write_unlock(&rx->call_lock);
 455
 456         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
 457
 458         if (conn)
 459                 rxrpc_disconnect_call(call);
 460
 461         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
 462                 rxrpc_free_skb(call->rxtx_buffer[i],
 463                                (call->tx_phase ? rxrpc_skb_tx_cleaned :
 464                                 rxrpc_skb_rx_cleaned));
 465                 call->rxtx_buffer[i] = NULL;
 466         }
 467
 468         _leave("");
 469 }
 470
 471 /*
 472  * release all the calls associated with a socket
 473  */
 474 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 475 {
 476         struct rxrpc_call *call;
 477
 478         _enter("%p", rx);
 479
 480         while (!list_empty(&rx->to_be_accepted)) {
 481                 call = list_entry(rx->to_be_accepted.next,
 482                                   struct rxrpc_call, accept_link);
 483                 list_del(&call->accept_link);
 484                 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, ECONNRESET);
 485                 rxrpc_put_call(call, rxrpc_call_put);
 486         }
 487
 488         while (!list_empty(&rx->sock_calls)) {
 489                 call = list_entry(rx->sock_calls.next,
 490                                   struct rxrpc_call, sock_link);
 491                 rxrpc_get_call(call, rxrpc_call_got);
 492                 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET);
 493                 rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
 494                 rxrpc_release_call(rx, call);
 495                 rxrpc_put_call(call, rxrpc_call_put);
 496         }
 497
 498         _leave("");
 499 }
 500
 501 /*
 502  * release a call
 503  */
 504 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 505 {
 506         const void *here = __builtin_return_address(0);
 507         int n;
 508
 509         ASSERT(call != NULL);
 510
 511         n = atomic_dec_return(&call->usage);
 512         trace_rxrpc_call(call, op, n, here, NULL);
 513         ASSERTCMP(n, >=, 0);
 514         if (n == 0) {
 515                 _debug("call %d dead", call->debug_id);
 516                 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 517
 518                 write_lock(&rxrpc_call_lock);
 519                 list_del_init(&call->link);
 520                 write_unlock(&rxrpc_call_lock);
 521
 522                 rxrpc_cleanup_call(call);
 523         }
 524 }
 525
 526 /*
 527  * Final call destruction under RCU.
 528  */
 529 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
 530 {
 531         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
 532
 533         rxrpc_put_peer(call->peer);
 534         kfree(call->rxtx_buffer);
 535         kfree(call->rxtx_annotations);
 536         kmem_cache_free(rxrpc_call_jar, call);
 537 }
 538
 539 /*
 540  * clean up a call
 541  */
 542 void rxrpc_cleanup_call(struct rxrpc_call *call)
 543 {
 544         int i;
 545
 546         _net("DESTROY CALL %d", call->debug_id);
 547
 548         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 549
 550         del_timer_sync(&call->timer);
 551
 552         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 553         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 554         ASSERTCMP(call->conn, ==, NULL);
 555
 556         /* Clean up the Rx/Tx buffer */
 557         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
 558                 rxrpc_free_skb(call->rxtx_buffer[i],
 559                                (call->tx_phase ? rxrpc_skb_tx_cleaned :
 560                                 rxrpc_skb_rx_cleaned));
 561
 562         rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned);
 563
 564         call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
 565 }
 566
 567 /*
 568  * Make sure that all calls are gone.
 569  */
 570 void __exit rxrpc_destroy_all_calls(void)
 571 {
 572         struct rxrpc_call *call;
 573
 574         _enter("");
 575
 576         if (list_empty(&rxrpc_calls))
 577                 return;
 578
 579         write_lock(&rxrpc_call_lock);
 580
 581         while (!list_empty(&rxrpc_calls)) {
 582                 call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
 583                 _debug("Zapping call %p", call);
 584
 585                 rxrpc_see_call(call);
 586                 list_del_init(&call->link);
 587
 588                 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
 589                        call, atomic_read(&call->usage),
 590                        rxrpc_call_states[call->state],
 591                        call->flags, call->events);
 592
 593                 write_unlock(&rxrpc_call_lock);
 594                 cond_resched();
 595                 write_lock(&rxrpc_call_lock);
 596         }
 597
 598         write_unlock(&rxrpc_call_lock);
 599 }